There is known a technology for reducing noise due to wind noise by forming a sound path extending to a sound collection member such that the sound path does not have a linear shape.
However, in a technology of the related art such as that described above, it is difficult to obtain, at the position of a sound collection member, acoustic characteristics with which significant resonance will not occur in up to a high voice frequency band. In recent years, the trend has been toward faster transmission speed in telecommunications and also toward wider bandwidth of voice transmission as a telephone function. In addition, in recent years, a new high-quality audio codec (for example, an enhanced voice services (EVS) codec technology) has been developed by using high-speed transmission such as long term evolution (LTE), and this has enabled sound transmission within a voice frequency band in the range of 50 Hz to 14 kHz, which is a high frequency.
The followings are reference documents:
[Document 1] Japanese Laid-open Patent Publication No. 2009-212844; and
[Document 2] Japanese Laid-open Patent Publication No. 08-322096.